50 no-progress move draw rule

While doing some work related to FEN (Forsyth–Edwards Notation), I ran into the FEN halfclock section, which records the moves to check for the 50-moe rule ( https://en.wikipedia.org/wiki/Fifty-move_rule ).

Is this a rule that's currently in use?

If so, how would a chess player know when to invoke it?

It is a standard draw rule in chess. 50 moves with no captures or pawn moves and a draw can be claimed. 

Good question. My *guess* is that a player seeing that he is going to be on the defensive in an endgame that is tricky and lengthy for his opponent to win (especially KBN vs K, or KQ vs KR) would mark on his score sheet the point at which the all-pieces endgame began, and watch (eagerly) for his opponent to reach the 50-move mark without mating.

I had this happen once. I was on the defensive vs a higher rated opponent (in other words, he wasn't accepting a draw, and was going to test me for 50 moves).

You find the last capture or pawn move on the scoresheet, then add 50.

Sometimes people add incorrectly though. For example lets say the last pawn move or capture was white's 44.gxf

As black, you could claim a draw on your 93rd move (because your 44th move was already move 1).

In the USCF you write down the move without actually making it, stop the clock (don't start your opponent's clock, pause the clock), and claim a draw on 50 move rule. You don't e.g. ask "draw?" because that only counts as a draw offer. In that case your opponent could ignore you and keep playing.

After you claim the draw (even if it's incorrect), your opponent can agree. If your opponent thinks it's incorrect they can get the tournament director and claim it hasn't been 50 moves yet.

On Chess.com, If I have five or more minutes left on my clock, I just make my moves and wait until I have one or two minutes left.  More than 50 moves will have been made by that time (If I'm really short on time, I wait until I have 10-20 seconds left and make the claim.  Either 50 moves will have been made or I'm going to lose the game anyway).

In an  OTB, game, when your time left is less than five minutes, you don't have to keep score.  Thus there is no record to make a 50-move claim.  In that case you can ask the TD to have someone count the moves once you have less than five minutes.  However, with the use of delays and increments these days, it soon becomes obvious that the game will go on forever, and both players will eventually agree to a draw (probably long before 50 moves are reached)

Note:  I'm using an old version of the USCF rules, I don't think that things have changed in the new edition.  FIDE rules differ from USCF rules.

Yeah, good point, you can ask the TD to start counting moves.

You can't rely on your opponent to agree if your position is more difficult though. Sometimes your position will even be lost. Lets say the knight + bishop mate, but your opponent doesn't quite remember how to do it. Or queen vs rook. They'll probably take 100 moves if you let them have it!

 The only games where I have invoked the 50-move rule are a handful of games on Chess.com.  They're usually K+R vs K+R or BOC with one or two locked up pawns.  OTB, I've had one KBN vs K game where my opponent had no clue how to play it.  After about 20 moves, he agreed to a draw (it was a casual game, and he decided that he'd rather start a new game).

It is certainly a rule today. However, occasionally in recent years, tournaments have been able to extend it via specific declaration as some tablebase endings show a clear win in more than fifty moves.

There's a bit of history on the implementation of this rule in the nineteenth century at http://chessskill.blogspot.com/2016/06/max-judds-draw-claim.html

Yeah, I think for a short amount of time FIDE was allowing some mates longer than 50 moves  (with no pawn moves or captures) but they reverted back to the regular 50 moves and added an automatic draw at 75 moves (under the same conditions).

My recollection is this: when tablebases found forced mates in slightly more than 50 moves, they fiddled with the rule. When tablebases found forced wins in over 300 moves in pawnless endings, they realized that accounting for such positions in the rules would be madness.

FIDE is fine with leaders who have been diplomats on alien spacecraft, but they don't otherwise cultivate madness.

One of the high school players I coached, in a rated tournament, had a K vs his opponent's K, N, and B and I had taught him in that situation, during club meetings, to keep his K from the two corners of the board where the corner square was the same color as that on which his opponent's B traveled.

Around move 30 into the 50 move draw sequence, he realized his opponent was pushing his King to a mating corner. So, to rattle his opponent, on his next move, he picked up his King, slammed it down on the board on it's new square, and called out, "Thirty-one!"  The opponent began to have trouble concentrating and let my player's K slip out of the mating net.  When it got to "Forty!" the opponent began making desperation moves that just resulted in wasted time.  When my guy called out "Fifty! Draw!" the opponent immediately got up from the board and walked away, nearly in tears!

That's one of many tactics available in OTB games you don't see online.  Another one where I was the Tournament Director and asked to intervene occurred in the following very clever situation.

One player, while his opponent was on the move, was in trouble on the board but saw that he had a mate in one if his opponent overlooked it.

So the player in trouble wrote down at his next move, in big letters in his scorebook, "Resign."  His opponent saw it and figured it didn't matter what he played so he made a simple move - which was the player-in-trouble's intent!

The guy who wrote "Resign" grabbed his piece, moved it, yelled "Checkmate!" and hit his clock button, erased "Resign" and entered the winning move in his book.

The opponent who was checkmated asked me to rule that the guy had to Resign because he wrote it in his scorebook.  I told him there is no USCF rule requiring him to do that. In fact, a lot players have the habit of writing their move in the scorebook, then looking at the board again - often changing their minds. He could write "I quit chess," and keep playing forever as far as USCF cares.  What happens on the board is all that matters!

Haha, that's pretty sneaky.